1. Field of Invention
The present invention relates to a liquid crystal display device and an electronic apparatus, and particularly, to a transflective liquid crystal display device that displays both in reflective and transmissive modes to achieve a high-contrast, wide-viewing-angle display.
2. Description of Related Art
Related art liquid crystal display devices having both a reflective mode and a transmissive mode are transflective liquid crystal display devices. In a transflective liquid crystal display device, a liquid crystal layer is disposed between an upper substrate and a lower substrate. Provided on the inner surface of the lower substrate is a metallic reflective film formed of, for example, aluminum having apertures for light transmission. This reflective film functions as a transflector. In the reflective mode, external light incident on the upper substrate passes through the liquid crystal layer and is then reflected by the reflective film disposed on the inner surface of the lower substrate. The reflected light passes through the liquid crystal layer again and is emitted from the upper substrate so as to achieve display. On the other hand, in the transmissive mode, light emitted from a backlight enters the lower substrate and then passes through the apertures of the reflective film. The light passes through the liquid crystal layer and is then emitted outward from the upper substrate to achieve display. Accordingly, the apertures disposed in the reflective film function as transmissive display areas and the other areas function as reflective display areas.
The related art transflective liquid crystal display device, however, is disadvantageous in having a narrow viewing angle for the transmissive display. To prevent parallax error, the transflector is disposed on the inner surface of the liquid crystal cell. For this reason, the reflective display is performed with only a single polarizer provided adjacent to the viewer, leading to a restricted optical layout. To address this problem, a related art type of liquid crystal display device that uses homeotropic liquid crystal alignment is disclosed by “Development of transflective LCD for high contrast and wide viewing angle by using homeotropic alignment”, M. Jisaki et al., Asia Display/IDW'01, p.133–136 (2001). The liquid crystal display device of this type has the following three characteristics.
(1) The device uses a “VA (vertical alignment) mode” in which liquid crystals having negative dielectric anisotropy are aligned vertically on the substrate and are tilted when a voltage is applied.
(2) The device uses a “multi-gap structure” in which the thickness of the liquid crystal layer (cell gap) in the transmissive display areas is different from that in the reflective display areas Japanese Unexamined Patent Application Publication No. 11-242226.
(3) The device uses a “multi-domain structure”. This means that each transmissive display area is octagonal, and the transmissive display area on an opposing substrate has a protrusion at the central area so that liquid crystal molecules are tilted in multiple directions within this area.